Telecommunications is a rapidly evolving industry that has exploded into the market in recent years with all types of mobile communications devices and systems. The advent of the Internet and its vast IP (Internet Protocol) capabilities has opened the door for telecommunications to find ways of providing services that heretofore were not available to the cellular user. However, this rapid convergence of telecommunications systems and the Internet also leaves behind working legacy systems that without some mechanism for bridging the gap into the new technology, will leave customers and companies frustrated. The jump from an existing technology to a newer technology is costly both in terms of corporate resources costs and customer loyalty. Thus, such migrations need to be transparent to the customer, as well as cost effective for the telecom companies.
As defined in the 3GPP (3rd Generation Partnership Project) technical specification TS 23.002 v.6.7.0 (2005-03), the HSS (Home Subscriber Server) is the master database for a given user. The HSS is the entity that contains the subscription-related information to support the network entities actually handling calls/sessions. The HSS concept, developed by the 3GPP standards organization, is designed to address many of the shortcomings of the current 2G (2nd Generation) HLR (Home Location Register) for supporting 3G technology and services.
To support 3G technologies and services, the HSS is designed to inter-network with an IMS (IP Multimedia Subsystem) system, thus introducing new interfaces and requirements. The IMS represents a 3GPP and 3GPP2 effort to define an all-IP based wireless network as a replacement for the disparate voice, data, signaling, and control network elements, and enables the support for IP multimedia applications within the UMTS (Universal Mobile Telecommunications System). The UMTS is a 3G broadband packet-based transmission of text, digitized voice, video, and multimedia that offers a consistent set of services to mobile computer and phone users no matter where they are located in the world.
The telecom industry is currently shifting towards all-IP systems, driven by the fundamental need to reduce costs, create new revenue generating services and to protect the operator business model, and IMS is a new core and service domain that enables the convergence of data, speech and network technology over an IP-based infrastructure. It is the operator choice of control and service logic for IP packet-based communication. For users, IMS-based services enable communications in a variety of modes that include voice, text, pictures and video, or any combination of thereof in a highly personalized and secure way. IMS is designed to fill the gap between the existing traditional telecommunications technology and Internet technology that increased bandwidth alone does not provide, and allows operators to offer new, innovative services that share holders and end users are expecting.
The HSS as specified by 3GPP supports legacy 2G and 2.5G technology (in both domains of CS-circuit switched and PS-packet switched). Requirements specific to the HSS have been or continue to be defined by the 3GPP organization. With most of the requirements already secured, the HSS concept, can become a reality. But the concern of how a carrier should introduce the HSS into a production system remains to be determined.
One concept is introducing the HSS platform as a whole. Although simplistic in concept, this path is not preferred for many reasons. It will be another database type system that the carrier has to manage. Moreover, it will require provisioning development which would be costly and timely. Additionally, it is an inefficient use of capital expenses due to redundancy, since the 2G HLR will continue to be used for 2G services which will also be utilized to support 3G technology (e.g., presence services). Moreover, converting and migrating all applicable applications to the HSS would be costly and disruptive.
Conventionally, such migrations are solved by duplicating data in the network, and never leveraging existing data or business logic. For example, in order to deploy new services in a 3G network, a company will need to deploy subscriber service servers in the network. However, most of the data needed for these servers is already maintained in the network. Nonetheless, a carrier will need to duplicate and maintain multiple copies of the same data in the network. Accordingly, there is a substantial unmet need for a solution that when introducing the HSS, the existing 2G storage medium servicing the CS and PS domains can also be utilized.